Redundant control device for preventing circuit malfunction
By setting up redundant contacts in parallel connection in the electrical control system, the equipment downtime caused by hardware contact failure is solved, the system reliability and stability is improved, and the downtime incidents caused by poor contact in production are prevented.
Patent Information
- Application Number
- CN202421231758.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-31
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-05-31
AI Technical Summary
In existing electrical control systems, due to the increase in contact resistance of hardware contacts or poor contact, the magnetic relay or contactor fails, resulting in unexpected shutdown of equipment, affecting production and safety.
Design a redundant control device to ensure that the control loop remains on when the contact is faulty by setting the main and backup contacts in the start button, stop button, contactor and thermal relay, and connecting it in parallel, and adding redundant contacts. The parking incident occurred.
Effectively prevent unexpected equipment shutdown caused by contact failure, improve the reliability and stability of the control circuit, and avoid major losses and safety accidents caused by poor contact in production.
Smart Images
Figure CN222259870U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electrical control, and is a redundant control device for preventing circuit malfunction. Background Art
[0002] In the existing electrical control field, the reliability of the control system is mainly improved through control technologies such as computers, single-chip microcomputers, PLCs, and hardware such as secondary control elements. However, there are the following shortcomings: (1) For small control systems, the use of computers, single-chip microcomputers or PLCs is relatively expensive, and buttons, relays, contactors and other hardware are still mainly used to implement control functions. Due to the lack of redundant fault-tolerant design, the reliability is not high. (2) For large or complex control systems, computer configuration and programming methods are used in the design to logically implement self-diagnosis, fault-tolerant, and redundancy functions, but the input and output buttons and relay hardware circuits have no redundant fault-tolerant functions, which is a weak link.
[0003] At present, in actual production, for control circuits composed of electrical secondary components, due to the influence of many factors such as operating environment, maintenance quality, hardware quality, etc., the contact resistance of the hardware contacts closed during operation such as the stop button, emergency stop button, and protection interlock in the control circuit increases, the contact is poor or disconnected instantly, causing the magnetic retention of the relay or contactor to fail and accidentally disconnect, causing the running equipment to trip and stop, and a tripping event without signs or alarms occurs. For process equipment in important production processes, the occurrence of this situation will cause important key equipment to suddenly shut down, seriously affecting normal production. For example, in large coal chemical enterprises, if a key equipment unexpectedly shuts down, it will cause the entire production system to shut down, with direct losses of more than one million yuan, or even safety accidents.
[0004] Specifically, as attached Figure 1 As shown in the figure, in the basic self-holding secondary control circuit, at least electrical components such as secondary power switch, start button, stop button, contactor, thermal relay, etc. are composed. The control principle is: turn on the secondary power switch, press the start button, the contactor coil is energized, the self-locking contact is closed, release the start button, the coil remains energized, the main circuit is connected, and the equipment starts to run. Press the stop button during operation, the contactor coil loses power, the main circuit is disconnected, and the equipment stops running. According to the above principle, during the operation of the equipment, if no one operates the stop button and the equipment has no faults that cause the thermal relay protection to operate, and due to other factors such as the environment, the normally closed contacts of the stop button, the normally open self-locking contacts of the contactor, or the normally closed contacts of the thermal relay FR are temporarily in poor contact, which will cause the contactor coil to lose power and the main circuit to be disconnected, causing the equipment to stop unexpectedly, affecting production output and product quality, and even causing significant losses. Utility Model Content
[0005] The utility model provides a redundant control device for preventing circuit malfunction, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problem of increased contact resistance of closed hardware contacts, poor contact or instantaneous disconnection causing magnetic retention failure of relays or contactors and causing the running equipment to trip and stop.
[0006] The technical solution of the utility model is achieved through the following measures: a redundant control device for preventing circuit malfunction, comprising a start button, a stop button, a contactor and a thermal relay, wherein the start button is provided with a group of main normally open contacts, the stop button is provided with a group of main normally closed contacts, the contactor is provided with a group of main normally open contacts, and the thermal relay is provided with a group of main normally closed contacts; wherein the main normally closed contacts of the stop button, the main normally open contacts of the contactor, the main normally closed contacts of the thermal relay and the coil of the contactor are connected in series in sequence, and the main normally open contacts of the start button are connected in parallel with the main normally open contacts of the contactor; the stop button is also provided with a group of spare normally closed contacts, and the spare normally closed contacts of the stop button are connected in parallel with the main normally closed contacts of the stop button.
[0007] The following are further optimizations and / or improvements to the above utility model technical solution:
[0008] The contactor may also be provided with a set of spare normally open contacts, and the spare normally open contacts of the contactor are connected in parallel with the main normally open contacts of the contactor.
[0009] The spare normally open contact of the above contactor can be an independent extended contact, which is snap-fitted to the contactor.
[0010] The above-mentioned thermal relay may also be provided with a set of spare normally closed contacts, and the spare normally closed contacts of the thermal relay are connected in parallel with the main normally closed contacts of the thermal relay.
[0011] An intermediate relay may also be provided, the coil of the intermediate relay being connected in parallel with the coil of the contactor, and the normally open contact of the intermediate relay being connected in parallel with the main normally open contact of the contactor.
[0012] The utility model adds redundant technical measures to the hardware contacts such as the emergency stop button and relay in the parking loop in the magnetically held electrical secondary control circuit. When a contact fails, the redundant contact plays a role to keep the control loop connected, thereby avoiding or reducing parking events caused by contact failures. The utility model is mainly used in key electrical equipment control circuits using magnetic holding, especially in relatively critical electrical equipment secondary control circuits, to prevent tripping events caused by increased resistance and poor contact of the control element hardware contacts. The utility model can ensure stable operation of important equipment in production process control and avoid unexpected shutdown events caused by poor contact of the control circuit contacts. The utility model is simple to implement, does not affect the normal function of the control loop, has a significant effect on improving the reliability of the control loop, has strong operability, and has a good promotion effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Attached Figure 1 This is a basic self-holding secondary control circuit diagram in the prior art.
[0014] Attached Figure 2 This is the secondary control circuit diagram of Example 1 of the utility model.
[0015] Attached Figure 3 This is the secondary control circuit diagram of Example 2 of the utility model.
[0016] The codes in the accompanying drawings are: QF1 is the power switch, SB1 is the stop button, SB2 is the start button, KM1 is the contactor, FR is the thermal relay, SB1-1 is the main normally closed contact of the stop button SB1, KM1-1 is the main normally open contact of the contactor KM1, FR-1 is the main normally closed contact of the thermal relay FR, KM1-Q is the coil of the contactor KM1, SB2-1 is the main normally open contact of the start button SB2, SB1-2 is the spare normally closed contact of the stop button SB1, KM1-2 is the spare normally open contact of the contactor KM1, KA is the intermediate relay, KA-Q is the coil of the intermediate relay KA, KA-1 is the normally open contact of the intermediate relay KA, and FR-2 is the spare normally closed contact of the thermal relay FR. DETAILED DESCRIPTION
[0017] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical solution of the present invention and actual conditions.
[0018] The utility model is further described below in conjunction with embodiments:
[0019] Embodiment 1: As attached Figure 2As shown, the redundant control device for preventing circuit malfunction includes a start button SB2, a stop button SB1, a contactor KM1 and a thermal relay FR. The start button SB2 is provided with a group of main normally open contacts SB2-1, the stop button SB1 is provided with a group of main normally closed contacts SB1-1, the contactor KM1 is provided with a group of main normally open contacts KM1-1, and the thermal relay FR is provided with a group of main normally closed contacts FR-1; wherein, the main normally closed contacts SB1-1 of the stop button SB1, the contactor KM1 is provided with a group of main normally open contacts KM1-1, and the thermal relay FR is provided with a group of main normally closed contacts FR-1. The main normally open contact KM1-1 of KM1, the main normally closed contact FR-1 of the thermal relay FR and the coil KM1-Q of the contactor KM1 are connected in series in sequence, and the main normally open contact SB2-1 of the start button SB2 is connected in parallel with the main normally open contact KM1-1 of the contactor KM1; the stop button SB1 is also provided with a set of spare normally closed contacts SB1-2, and the spare normally closed contacts SB1-2 of the stop button SB1 are connected in parallel with the main normally closed contact SB1-1 of the stop button SB1. During operation, if the main normally closed contact SB1-1 of the stop button SB1 has poor contact, the spare normally closed contact SB1-2 of the stop button SB1 keeps the circuit connected, so that the control circuit can operate normally, which increases the reliability of the control circuit and enables important equipment to operate stably for a long period of time.
[0020] Furthermore, the contactor KM1 is also provided with a set of spare normally open contacts KM1-2, and the spare normally open contacts KM1-2 of the contactor KM1 are connected in parallel with the main normally open contacts KM1-1 of the contactor KM1. The spare normally open contacts KM1-2 of the contactor KM1 can also be independent extended contacts, and the extended contact buckles are mounted on the contactor KM1. During operation, if the main normally open contact KM1-1 of the contactor KM1 has poor contact, the spare normally open contacts KM1-2 of the contactor KM1 keep the circuit connected, so that the control circuit can operate normally, further increasing the reliability of the control circuit. This situation is applicable to contactors with spare or extended contacts.
[0021] Furthermore, the thermal relay FR is also provided with a set of spare normally closed contacts FR-2, which are connected in parallel with the main normally closed contact FR-1 of the thermal relay FR. During operation, if the main normally closed contact FR-1 of the thermal relay FR fails to make contact, the spare normally closed contact FR-2 of the thermal relay FR keeps the circuit connected, so that the control circuit can operate normally, and the reliability of the control circuit is further increased.
[0022] The utility model adds redundant parallel connection points at the normally closed contact of the stop button, the normally open self-locking contact, and the normally closed contact of the thermal relay. During operation, if one contact has poor contact, there is another parallel connection point to keep the circuit connected, so that the control circuit can operate normally, the reliability of the control circuit is increased, and important equipment can operate stably for a long period of time. After the improvement, normal personnel operation and equipment fault protection functions are not affected.
[0023] In actual applications, for secondary electrical components such as buttons, relays, and contactors with spare or extended functions, extended contacts are directly connected in parallel with the original contacts of the circuit, such as stop buttons, emergency stop buttons, self-locking contacts, etc., and redundant functions of the contacts are realized by increasing the number of parallel contacts. For secondary electrical components such as buttons, relays, and contactors without spare or extended functions, buttons are replaced with buttons with extended functions, and relays or contactors are increased by adding extended relays to increase extended contacts, and then the extended contacts are connected in parallel with the original contacts of the circuit to realize redundant functions and improve reliability. The embodiment of the utility model analyzes the control principle of the equipment, identifies the secondary auxiliary contacts in the secondary control circuit that can cause parking, mainly the stop button, emergency stop button, interlocking contacts, self-locking contacts, etc., and then adopts the technical solution of parallel redundant contacts to achieve the purpose of improving the reliability of the control circuit.
[0024] The embodiment of the utility model draws on the redundant technical solution of computer control, and adds redundant technical measures to the hardware contacts such as the emergency stop button and relay in the parking loop in the magnetically held electrical secondary control circuit. When a contact fails, the redundant contact plays a role to keep the control loop connected, avoiding or reducing parking events caused by contact failures. The embodiment of the utility model is mainly used in the control circuit of key electrical equipment using magnetic retention, especially in the secondary control circuit of relatively critical electrical equipment, to prevent tripping events caused by increased resistance and poor contact of the hardware contacts of the control element. The embodiment of the utility model can make important equipment in the production process control run stably, and avoid unexpected shutdown events caused by poor contact of the control circuit contacts. The embodiment of the utility model is simple to implement, does not affect the normal function of the control loop, has a significant effect on improving the reliability of the control loop, has strong operability, and good promotion effect.
[0025] Embodiment 2: As attached Figure 3 As shown, in the redundant control device for preventing circuit malfunction, an intermediate relay KA is also provided, the coil KA-Q of the intermediate relay KA is connected in parallel with the coil KM1-Q of the contactor KM1, and the normally open contact KA-1 of the intermediate relay KA is connected in parallel with the main normally open contact KM1-1 of the contactor KM1.
[0026] During operation, if the main normally open contact KM1-1 of contactor KM1 has poor contact, the normally open contact KA-1 of intermediate relay KA will keep the circuit connected, so that the control circuit can operate normally, further increasing the reliability of the control circuit.
[0027] The embodiment of the utility model is applicable to contactors without spare or extended contacts, and uses intermediate relays to expand contacts, which can make important equipment in production process control run stably and avoid unexpected shutdown events caused by poor contact of control circuit contacts. The embodiment of the utility model is simple to implement, does not affect the normal function of the control circuit, has a significant effect on improving the reliability of the control circuit, has strong operability, and has a good promotion effect.
[0028] The above technical features constitute the embodiments of the present utility model, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.
Claims
1. A redundant control device for preventing circuit malfunction, characterized in that It includes a start button, a stop button, a contactor and a thermal relay. The start button is provided with a group of main normally open contacts, the stop button is provided with a group of main normally closed contacts, the contactor is provided with a group of main normally open contacts, and the thermal relay is provided with a group of main normally closed contacts; wherein the main normally closed contacts of the stop button, the main normally open contacts of the contactor, the main normally closed contacts of the thermal relay and the coil of the contactor are connected in series in sequence, and the main normally open contacts of the start button are connected in parallel with the main normally open contacts of the contactor; the stop button is also provided with a group of spare normally closed contacts, and the spare normally closed contacts of the stop button are connected in parallel with the main normally closed contacts of the stop button.
2. The redundant control device for preventing circuit malfunction according to claim 1, characterized in that The contactor is also provided with a set of spare normally open contacts, and the spare normally open contacts of the contactor are connected in parallel with the main normally open contacts of the contactor.
3. The redundant control device for preventing circuit malfunction according to claim 2, characterized in that The spare normally open contacts of the contactor are independent extended contacts, which are snap-fitted to the contactor.
4. The redundant control device for preventing circuit malfunction according to claim 1, 2 or 3, characterized in that The thermal relay is also provided with a set of spare normally closed contacts, and the spare normally closed contacts of the thermal relay are connected in parallel with the main normally closed contacts of the thermal relay.
5. The redundant control device for preventing circuit malfunction according to claim 1, characterized in that An intermediate relay is also provided, the coil of the intermediate relay is connected in parallel with the coil of the contactor, and the normally open contact of the intermediate relay is connected in parallel with the main normally open contact of the contactor.
6. The redundant control device for preventing circuit malfunction according to claim 2, characterized in that An intermediate relay is also provided, the coil of the intermediate relay is connected in parallel with the coil of the contactor, and the normally open contact of the intermediate relay is connected in parallel with the main normally open contact of the contactor.
7. The redundant control device for preventing circuit malfunction according to claim 3, characterized in that An intermediate relay is also provided, the coil of the intermediate relay is connected in parallel with the coil of the contactor, and the normally open contact of the intermediate relay is connected in parallel with the main normally open contact of the contactor.
8. The redundant control device for preventing circuit malfunction according to claim 4, characterized in that An intermediate relay is also provided, the coil of the intermediate relay is connected in parallel with the coil of the contactor, and the normally open contact of the intermediate relay is connected in parallel with the main normally open contact of the contactor.